462 www.frontiersinecology.org © The Ecological Society of America Write Back Considering that truffles were har- vested throughout Europe during the 17th century, the Burgundy truffle might have, similarly to the Périgord truffle (Murat et al. 2004), recolonized Europe from some southern refugia, possibly following the last ice age. The observed corre- lation is not necessarily evidence of a climate-driven range expansion, however, given that other factors (eg competition with other fungi, shift in host-plant range) might lead to such a finding. Clearly, more specimens and a more comprehen- sive approach, accounting for all variables (eg climate, soil, associ- ated species), will be needed to identify the possible driving forces behind the Burgundy truffle’s cur- rent distribution. Here, our analysis suggests that cli- mate change that started in the late 19th century has had little effect on the present distribution of the Burgundy truffle. Büntgen et al.’s conclusions might nevertheless apply to other truffle species with narrower ranges and higher commer- cial values (eg Périgord or Piedmont truffles). If climate does limit the dis- tribution of the latter two species, even the slight warming in northern Europe envisioned by Büntgen et al. might induce northern expansion. In addition to temperature, other fac- tors – including precipitation, soil properties (Chevalier et al. 2001), and mating type (Rubini et al. 2011) – determine whether truffles produce fruiting bodies. Successful truffle cul- tivation will consequently succeed only if truffle orchard management shifts from current empirical prac- tices to practices based on scientific evidence. Increasing temperatures alone will not be sufficient for suc- cessful truffle cultivation in more northern parts of Europe. Richard Splivallo 1* , Rengenier Rittersma 2 , Nayuf Valdez 1 , Gérard Chevalier 3 , Virginie Molinier 4 , Daniel Wipf 4 , and Petr Karlovsky 1 1 Molecular Phytopathology and Mycotoxin Research, University of Goettingen, Goettingen, Germany * (ricsi17@hotmail.com); 2 Beltheim-Heyweiler, Germany; 3 Résidence Cristelle, Cournon d’Auvergnes, France; 4 UMR 1347 Agroécologie AgroSup/INRA/uB, Pôle IPM CNRS ERL 6300, Dijon, France Brückmann FE. 1730. Epistolae itinerar- ium XX: de tuberibus terrae. Wolfenbüttel, Germany. Calosi P, Bilton DT, Spicer JI, et al. 2010. What determines a species’ geo- graphical range? Thermal biology and latitudinal range size relation- ships in European diving beetles (Coleoptera: Dytiscidae). J Anim Ecol 79: 194–204. Chevalier G and Frochot H. 1997. La truffe de Bourgogne: Tuber uncinatum Chatin. Levallois-Perret, France: Edi- tions Pétrarque. Chevalier G, Gregori G, Frochot H, and Zambonelli A. 2001. The cultivation of the Burgundy truffle. In: Bencivenga M and Granetti B (Eds). Proceedings of the Second International Conference on Edible Mycorrhizal Mushrooms. 3–6 Jul 2001. Spoleto, Italy: Comunità Montana dei Monti Martani e del Serano. Hall IR, Yun W, and Amicucci A. 2003. Cultivation of edible ectomycorrhizal mushrooms. Trends Biotechnol 21: 433–38. Murat C, Díez J, Luis P, et al. 2004. Polymorphism at the ribosomal DNA ITS and its relation to postglacial re- colonization routes of the Perigord truffle Tuber melanosporum. New Phytol 164: 401–11. Paolocci F, Rubini A, Riccioni C, et al. 2004. Tuber aestivum and Tuber uncina- tum: two morphotypes or two species? FEMS Microbiol Lett 235: 109–15. Rittersma RC. 2010a. Die verspätete Trüffelnation. Zu Geschichte, Gegen- wart und Zukunft der Trüffel in Deutschland. In: Dumaine JM and Wojtko N (Eds). Trüffeln: die heimis- chen Exoten. Aarau/München, Ger- many: AT Verlag. Rittersma RC. 2010b. Only the sky is the limit of the soil. Manifestations of truf- fle mania in Northern Europe in the 18th century. In: Bencivenga M and Granetti B (Eds). Proceedings of the Second International Conference on Edible Mycorrhizal Mushrooms. 3–6 Jul 2001. Spoleto, Italy: Comunità Montana dei Monti Martani e del Serano. Robinson T. 1691–1693. An account of the Tubera Terrae, or truffles found at Rushton in Northamptonshire. Philos T Roy Soc London 7: 824–26. Rubini A, Belfiori B, Riccioni C, et al. 2011. Tuber melanosporum: mating type distribution in a natural plantation and dynamics of strains of different mating types on the roots of nursery-inocu- lated host plants. New Phytol 189: 723–35. Splivallo R, Valdez N, Kirchhoff N, et al. 2012. Intraspecific genotypic variabil- ity determines concentrations of key truffle volatiles. New Phytol 194: 823–35. Wedén C, Danell E, and Tibell L. 2005. Species recognition in the truffle genus Tuber – the synonyms Tuber aestivum and Tuber uncinatum. Environ Microbiol 7: 1535–46. doi:10.1890/12.WB.020 Illuminating the mysterious world of truffles On the basis of discovering ~2 kg of truffles (belonging to several Tuber spp, including a >410-g mature Bur- gundy truffle [T aestivum syn uncina- tum]) at >70 sites in southwest Germany, we postulated in our origi- nal letter that ongoing climate change was one possible factor contributing to species-specific range shifts, as well as to variation in fruiting body produc- tion and maturation, in truffles. A warming-induced extension of the growing period – together with redistributed precipitation regimes – was hypothesized to likely affect the optimum rather than the entire distri- bution of individual truffle species. The detection of not only T aestivum but also T brumale, T excavatum, T fulgens, T macrosporum, T mesenter- icum, and T rufum in the same region and at the same time, together with substantial temperature anomalies, suggested that climatic effects were involved. Associated environmental changes may have impacted condi- tions at local to regional scales but did not necessarily shift the geographic scope of entire ecosystems. Our “hypogeous evidence”, in line with European-wide myco-phenological observations (Kauserud et al. 2012), supports a reported long-term decline in Périgord black truffle (T melanospo- rum) harvests across its natural and cultivated Mediterranean habitats (Hall et al. 2003; Mello et al. 2006). A possible reason for this southern European truffle yield decrease is a loss in soil moisture. Nevertheless, we agree with Spli-